Researchers identified bacterial genes that can extend the life of worms, and some that can also protect the worms from tumor growth.

Supplements that contain these beneficial gut bacteria could one day be used to slow the ageing process, the researchers say.

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Because it is difficult to conduct this kind of research in mammals, the researchers studied C.elegans, a transparent, miscroscopic laboratory worm that is as long as a pinhead and shared essential characteristics with human biology

Researchers at Baylor College of Medicine and the University of Texas Health Science Center at Houston identified bacterial genes and compounds that extend the life of C.elegans worms, as well as some genes that slow down tumor progression and the accumulation of amyloid-beta, a compound associated with Alzheimer's disease.

HOW THEY DID IT

Researchers at Baylor College of Medicine and the University of Texas Health Science Center identified bacterial genes and compounds that extend the life of C.elegans lab worms worms.

Many researchers use this worm to study basic biological processes, since its short life cycle of two to three weeks allows for rapid data collection.

They studied the effects of each gene in an E.coli bacteria 'library' by deleting one gene from each of 4,000 genes at a time.

They fed C.elegans worms each individual mutant bacteria and then looked at the worm's life span.

'Of the nearly 4,000 bacterial genes we tested, 29, when deleted, increased the worms' lifespan,' said Dr Meng Wang, the corresponding author of the study.

'Twelve of these bacterial mutants also protected the worms from tumor growth and accumulation of amyloid-beta, a characteristic of Alzheimer's disease in humans.'

'The scientific community is increasingly aware that our body's interactions with the millions of microbes in our bodies, the microbiome, can influence many of our functions, such as cognitive and metabolic activities and aging,' said the corresponding author of the study, Dr Meng Wang, associate professor of molecular and human genetics at Baylor and the Huffington Center On Aging.

'In this work we investigated whether the genetic composition of the microbiome might also be important for longevity.'

Because it is difficult to conduct this kind of research in mammals, the researchers studied C.elegans, a transparent, miscroscopic laboratory worm that is as long as a pinhead and shared essential characteristics with human biology.

The worm has a two to three week long lifespan, during which it feeds on bacteria, develops into an adult, reproduces and progressively ages, losing strength, health and dying.

Many researchers use this worm to study basic biological processes, since its short life cycle allows for rapid data collection.

'We think that C. elegans is a wonderful system in which to study the connection between bacterial genes and aging because we can very fine tune the genetics of microbes and test many genes in the worm in a relatively short time,' Dr Wang said.

So to study the effect of individual bacterial genes on the lifespan of the C.elegans worm, Dr Wang joined Dr Christophe Herman, associate professor of molecular and human genetics and molecular virology and microbiology at Baylor, and other colleagues who are experts in bacterial genetics.

When the researchers gave pure colanic acid to the worms, they also lived longer.

Colanic acid also increase lifespan in lab fruit flies and mammalian cells grown in the lab.

Based on their findings, the researchers suggest that it might be possible to design supplements of bacteria or their compounds that could slow the aging process.

The researchers also found that colanic acid regulates the dynamics of the mitochondria - cellular structures that provide energy to the cell.

Other 'mutant bacteria' tested increased lifespan by over-producing a carbohydrate molecule called colanic acid. The researchers also found that colanic acid regulates the dynamics of the mitochondria - cellular structures that provide energy to the cell

'These findings are also interesting and have implications from the biological point of view in the way we understand host-microbe communication,' Dr Wang said.

'Mitochondria seem to have evolved from bacteria that millions of years ago entered primitive cells.

'Our finding suggests that products from bacteria today can still chime in the communication between mitochondria in our cells.

'We think that this type of communication is very important and here we have provided the first evidence of this.

'Fully understanding microbe-mitochondria communication can help us understand at a deeper level the interactions between microbes and their hosts.'